Researchers from the University of Burgos have patented a synthetic process of cationic Iridium(III) complexes with formula (I). Moreover, they have developed a one-pot protocol for the regioselective synthesis of 3-thiocyanato indoles (II) from their corresponding indolines. On the other hand, the use of these Ir(III) complexes as potential therapeutic photosensitizers for antitumor photodynamic therapy is also protected.
New and innovative aspects
The Iridium(III) complexes described in this patent exhibit singular characteristics that differentiate them from known complexes. They show significant activity as photocatalysts or photosensitizers, absorbing energy from light and transferring it to oxygen to form reactive oxygen species (ROS) that act as efficient and environmentally friendly oxidants. Furthermore, the synthesis of the Iridium(III) complexes is carried out under mild conditions and shows good yields.
Main advantages of its use
- High stability of Iridium(III) complexes in solution.
- They present excellent photostability under different light sources, then the range of possible applications increases considerably.
- As photocatalysts, the use of the low energy visible-light prevents secondary reactions from taking place and therefore the reactions are more selective.
- The one-pot regioselective synthesis of 3-thiocyanato indoles from indolines, is more economical, since it is not necessary to isolate and purify the intermediate products.
- In therapeutic applications, the new complexes show high photocytotoxicity index (PI = IC50,dark/IC50,light).
The cationic Iridium(III) complexes of formula (Mn+)(X-)n show two 2-phenylpyridinate ligands coordinated to the Ir(III) ion through the nitrogen atom of the pyridine ring and one of the carbon atoms of the phenyl group; and a ligand derived from β -carboline, which is bonded to the Ir(III) via two nitrogen atoms. These complexes can be used as photocatalysts in organic synthesis or as photosensitizers.
In organic synthesis, these complexes allow the regioselective synthesis of 3-thiocyanato indoles from indolines through a one-pot process. First, the process involves two steps: dehydrogenation of indolines and, subsequently, thiocyanation of the intermediate indoles. Both reaction steps imply the use of oxygen in the presence of light and the use of Iridium(III) complexes as photocatalysts.
Potential applications of the new Ir(III) complexes are as follow:
- Photooxidation reactions in organic synthesis
- Use as photocatalysts in thiocyanation reactions of indoles.
- Photosensitizers in photodynamic therapy in the treatment of cáncer.
- Preparation of a drug for the treatment of cancer, in combination with radiotherapy, that is, the drug is administered together with, or before, the administration of radiotherapy.
Intellectual property status
Protected by patent P202031190
Current development status
The technology related to the synthesis method is developed.
Desired business relationship
Commercial agreement; License agreement; Technical cooperation: further development; Technical cooperation: testing new applications; Technical cooperation: adaptation to specific needs.